Technical Abstract:
Fungi isolated from soybean cyst nematode were examined for production of nematode-antagonistic compounds. Fusarium equiseti produced inhibitors of root-knot nematode (Meloidogyne incognita) egg hatch and juvenile mobility. Bioassay-guided fractionation of a culture broth extract identified two active compounds, the trichothecenes 4,15-diacetylnivalenol and diacetoxyscirpenol. Trichothecenes possess broad spectrum toxicity, limiting their usefulness as templates for control agents. A second fungus species is also being examined. An Amberlite XAD extract of the culture broth was fractionated using medium-pressure chromatography (Toyopearl resin and silica gel) and reversed-phase HPLC. The identities of the nematode-antagonistic compounds from the second fungus species are being determined. Efforts to identify natural products from fungi associated with plant-parasitic nematodes can provide lead compounds for new control agents and increase our understanding of nematode-fungus interactions.